TARA and the secret to aging gracefully:
An unsciency lesson on the science of wine aging.
Because there is nothing like an ironic acronym to help one remember important details, I’ve developed what I like to call the **TARA technique to assessing a wine’s aging potential. It involves the study of the following four elements:
(1) Tannins. (2) Acidity. (3) Residual Sugar. (4) Alcohol.
** If the irony of TARA being used as an acronym to unlock the secrets of graceful aging is lost on you, take time to download this season of Marriage Boot Camp: Reality Stars).
In the matter of Science vs. Booze…
But why do we need an acronym? Can’t we just check the “Best Before” date? Alas, no. Because, despite the fact that wine has been drunk for thousands of years by hundreds of clever, curious, well-funded, highly-motivated individuals, no one has discovered a sure-fire way to predict exactly how long a wine will take to reach its peak. Or be reduced to vinegar.
“If wine was a poor inner-city neighbourhood, oxygen molecules would be juvenile delinquents looking to break stuff…”
Perhaps part of the reason for no one ever having gathered the necessary data is because, while it might be possible to punch variables into a complex algebraic equation and decipher a best-before date, it’s more enjoyable to punch a hole in a cork and decipher the location of your nearest glass. So no one really bothers.
Which brings us back to T.A.R.A …
SO, in the absence of an app, equation, or reference table, we have to use old-fashioned observation. Luckily, by examining the prevalence of tannins, acidity, residual sugar, and alcohol in a wine, we can at least make snappy-but-educated guesses as to how long a wine may continue to improve…or at least survive. (This info is almost always available under “technical specs” on the winemaker or estate website).
If wine was a poor inner-city neighbourhood, oxygen molecules would be juvenile delinquents looking to break stuff, and tannins would be those selfless social workers, who keep them out of mischief by teaching them to knit, or play badminton.
Tannins form part of a group of compounds called polyphenols that bond to a bunch of other chemicals in weird and wonderful ways. One of the chemicals they bond to is oxygen. These delinquent oxygen molecules would otherwise set about wreaking havoc with certain elements in the wine, but INSTEAD, oxygen hangs out with these phenolic compounds & can, given the right opportunities and a good education, become healthy citizens, who contribute to society.
While tannins may busy themselves with both each other, and youthful, anarchic oxygen molecules, acidity’s trump card is its ability to make life awfully unpleasant for any bacteria that may cause wine to spoil prematurely.
If tannins are social workers, Acidity is Simon Cowell on X-Factor destroying the self-esteem of young hopeful bacteria everywhere. It does this by shifting the pH of the solution down the scale to a point where bacteria cannot survive.
“In general, a wine should have a pH of somewhere between 3 and 4 to be stable and not allow bacteria to grow and thrive,” Max Meindl, all-round organic chemistry biscuit, and superbly knowledgeable founder of Max on Wine.
If bacteria are high schoolers on prom night, sugar is the semi-palsied history teacher monitoring the distance between adolescent bodies. “Always leave room for the Holy Ghost”, says Prof Sugar, cutting the grass of every bacterium looking to get a legover before Jocund Day can get onto his tiptoes.
There are various mechanisms by which sugar creates unromantic settings for would-be bonking bacteria (they don’t actually bonk), but the only mechanism I’d suggest further reading on right now is that of water activity.
If you want to learn more about how sugar reduces water activity, and therefore stops bacteria from having a right old time, this is as good a link as any. And here is piece from Royal Coffee on role of WA in green coffee beans.
While part of the aim of this piece has been to avoid getting technical, I reckon that the use of a bit of lab-speak is worth the risk of losing you. Mostly because I think it’s cool the way that alcohol deals with bacteria.
Alcohol acts like the blob from the 80s horror film “The Blob”. It dissolves lipids in a bacteria’s outer membranes, and then, when the poor little critter starts to bleed out like a doomed high school cheerleader in the back of jalopy, the alcohol rushes into the cell and starts denaturing proteins. Meditate on that one when you’re next hungover, and you’ll realise, “heck, I got off pretty darn lightly with nausea and a headache!”